Friday, June 13, 2008
Keep boxwoods free of mulch, organic material
John Arbogast
Landscape consultant John Arbogast answers your questions every Thursday. Send questions about your lawn, garden, plants, or insects to:
Dear John
5102 Greenfield St. SW
Roanoke, Va. 24018
Or send an e-mail. Answers will be given only in this column. Please don't send pictures or samples.
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Q: I have several questions about caring for slow growing boxwoods. I have been fertilizing mine regularly, but I can’t see much difference in their growth. Someone told me that boxwoods don’t like to be fertilized. Is that true? What about mulching boxwoods I’ve tried to keep my boxwoods mulched, especially to help them survive this hot weather we’ve been having. Am I doing the right thing? I’m leaving leaves that have fallen from the boxwoods and blown into the boxwood trunks there to help hold moisture, which I think is important during this hot time of year. I live in Virginia.
A: Boxwoods generally don’t need to be fertilized. These are deep rooted ornamental shrubs that should be able to obtain nutrients they need for normal growth from the soil solution in Virginia. Adequate moisture is needed in order for boxwoods to absorb needed nutrients, meaning that weekly watering is helpful to boxwoods during dry times.
Take soil tests from boxwood ground if you are concerned about fertilizing or modifying soil acidity, which is also known as soil pH. Soil tests can be done in Virginia through Virginia Tech’s local Extension offices or through private labs.
Boxwoods don’t like to be mulched either. This is especially true in the area close to the boxwood trunks. A 2 inch thickness of organic mulch can be maintained over the soil at the dripline of the boxwood branches if the boxwoods are part of landscape beds that are mulched. Accumulation of organic mulch up against boxwood trunks can cause softening of the trunk’s bark there, possibly weakening the plants.
Even though your intentions in leaving organic debris under your boxwoods are well-meant, keeping those lower branches dry and allowing some air to circulate through the lower trunk area is essential to keep boxwoods healthy. Wear gloves to remove boxwood leaves that have fallen into the zone under each of your boxwoods as well as all other leaves that have blown under there. Remove this organic litter, and use it for a carbon source in your compost pile or to cover garden walking paths.
Q: I have an old 4-to-5-foot- tall camellia that was planted by my mother many years ago in the corner area about a foot from our small front porch and a foot out from the brick wall of the front of the house. Can this be moved, or should I try to prune it to make it look better? It appears to be cluttering the appearance of the foundation planting there. Also, what about balance in the landscape? There is a big rhododendron in front of the house about 7 or 8 feet on the left side of the front porch, but we lost a rhododendron several feet from the right side of the porch. Should I plant another rhododendron this fall in that right area to balance the rhododendron on the left side? The house is a brick two-story colonial in the Roanoke area.
A: I’m not sure that pruning can help the appearance of a camellia growing so close to your small porch and house brick wall. I’d suggest trying to move the old camellia with a big root ball this fall or next spring to another landscape place with partial shade and good soil where the big-growing plant will have room to grow and show off its beauty when conditions are favorable and you can water it weekly for its first year.
Transplanting time for successful plant moving should be when the conditions of mild soil plus plant dormancy or slow growth come together. Here in Roanoke, these times are usually in mid fall and in early spring.
Camellia roots are not particularly deep, but a wide root ball that is dug deep enough until no more roots are encountered would be suggested.
Plant balance is not necessarily a part of landscape design except for formal gardens. So, this means that you won’t need another rhododendron in that right front area, especially if such a big growing plant will eventually hide windows or make the front of your house look cluttered.
Balance can be important in the informal landscape if the front ground of a house slopes downward significantly. In those situations, plant larger shrubs on the front end of the lower region and lower shrubs on the higher ground.
Q: Could global warming be causing this early heat wave in the eastern United States and harsh weather in several parts of the country?
A: I’m just an old gardener and horticulture person and not a weather scientist, so I don‘t know. My opinion is that something is happening, but I don’t know whether it’s a change in a natural weather cycle or something else. I too am tired of having to water container plants in the yard so frequently, but this is just the way it is.
